For influencing the formation of mixture and the motion of a charge in cylinders of externally ignited piston-type internal-combustion engines, published International Application WO 91/14858 describes means in the region of the intake valves for a controllable flow deflection as the intake gas passes from the intake opening into the cylinder. An insufficient mixture formation is caused by an insufficient or missing vacuum in the intake pipe due to a poor fuel vaporization and cannot be improved at a fully open cross-sectional flow passage area of the valve because of the low intake velocity. Slides, gates, pivotal nozzles and the like are proposed as means for deflecting the flow. Such elements are arranged in the channel-like intake port immediately in the region of the intake opening and are operated by suitable setting means as a function of the operational condition of the engine. The setting means are actuated by a control device to so deflect the inflowing air/fuel mixture (hereafter designated as gas flow) under certain operational conditions that during the suction stroke within the cylinder chamber a turbulence (vortex) is generated whose rotary axis extends essentially transversely to the cylinder axis. It is a disadvantage of such an arrangement that the flow deflecting elements are disposed and supported in the intake port immediately upstream of the intake opening, that is, in a region in which only little room is available for additional structural components.